Igniting device



Feb; 4, 1936. 1 Q CARLSEN 2,029,356

IGNITING DEVICE 'Filed Aug. 3l, 1935 A INI/EN TOR. M5? 5 mm3/FM Patented Feb. 4, 1936 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to devices for igniting the fuel in a combustion chamber, or furnace, or the like, and is particularly well adapted for use in igniting oil or powderized coal.

The object of the invention is to provide an ignition vdevice adapted to be operated at a point remote from the ignition point, and to incorporate in such a device certain features of novel construction and arrangements whereby to provide greater safety and efficiency in the operation thereof. Other objects will appear as this specication proceeds, while reference is had to the accompanying drawing in which Fig. 1 is a View of an ignition device embodying the invention, with parts in section and parts broken away.

Fig. 2 is an enlarged view of the main parts of the ignition device with parts omitted and parts broken away.

Fig. 3 is a cross sectional view of the air valve.

Fig. 4 is a, wiring diagram.

In the drawing, the reference numeral I denotes the front wall of a furnace which has a combustion chamber 2 in which fuel is to be ignited by a flame travelling through the igniter pipe 3 to a point suitably located within the furnace. In the case of an oil burning furnace, the mouth 4 of the igniter pipe is simply projected within the combustion chamber in a position to ignite the oil. In the case of a furnace burning powdered coal, such as is illustrated in the drawing by way of example, the igniter pipe 3 is passed through the pipe 5 of the spreader head which includes inside the furnace the disk 6 which is cut to provide a number of vanes 'i to break up and spread the powdered coal in the usual manner. The spreader head or device is suitably supported within the. coal chamber 8 into which the coal is blown under pressure through a supply pipe 9. In this specification, the term spreader -head is intended to cover the pipe 5 and disk 6.

Referring now to the ignition device, the reference numeral I 2 denotes a gas supply pipe having a controlling valve I 3 and formed with a nozzle I 4 which extends into the igniter pipe 3, see Figure 2. The nozzle may be integral with the pipe as shown, or it may be a separate unit as may be preferred.

The pipe 3 forms an igniting fuel mixing chamber I5 for air and gas. Gas is supplied through the gas pipe I2 and the air is supplied by means of an air check valve I6 suitably connected to the pipe 3.

The valve I6 comprises a base I l or other means for suitably connecting the valve to the pipe 3. On the base, or directly on the pipe 3 if preferred, there is mounted a valve casing I8 having an air inlet I9 communicating with the outside air and an air outlet 20 communicating with the mixing chamber I5 as shown.

The valve inlet I9 is normally closed by a valve 2I which simply hangsdown by gravity and closes the inlet. A screw 22 or other means may be used to limit the opening movement of the valve. There may also be included in the 10 valve construction a baille plate 23 below the valve. 24 is a perforated dust cap placed on the valve.

Two spark plugs 25, 25 are mounted on the pipe 3 in advance of the gas nozzle. When the 15 valve 2| is open, air is admitted to the mixing chamber where it mixes with the gas and the resulting mixture is ignited by sparks from the spark plugs as will be obvious.

Means are provided whereby the operation of 20 the gas valve I3 automatically operates a switch for closing an electric circuit to the spark plugs.

As seen in Figure 2 the gas valve has a stem 26. The stem extends outside the valve body through an insulating plate 2l. In front of the latter 25 the stem carries a movable contact member 28 suitably insulated. The member 28 is adapted to move over and in contact with two brushes 29 and 30 suitably secured to the insulating plate 21. 30

As seen in Figure 4, the relation between the contact member 28 and the opening 3B in the gas valve is such that when the valve is opened by a clockwise movement thereof, the member 23 bridges the two brushes to close the circuit to the 35 Y spark plugs from a source of electricity 3I before the valve is wholly opened. When the valve is turned olf the circuit is open.

The operation is as followsr' When it is desired to ignite the furnace, the furnace draft is 40 opened and thereby there is caused a draft in the igniter pipe 3 and the air valve 2| is opened. When the gas valve is opened, the igniting fuel mixture in the mixing chamber is ignited by the spark plugs and the flame travels or is drawn 45 through the igniter pipe to the combustion chamber.

It follows, therefore, that if for some reason, designedly or accidentally, there is no draft in the combustion chamber, and igniter pipe 3 the 50 air valve cannot open, no ignition fuel mixture is created and there is no ignition. And of course no ignition is desired unless there is sucient draft in the combustion chamber to carry oiT the combustible gases. This applies to both oil and 55 coal furnaces. Thus it will be seen that the air check valve is a feature of great importance with respect to safety in operation.

When the valve is open air will pass downward behind the bafe plate 23 which may increase the draft by narrowing the opening to the pipe 3. If during the operation of the furnace, the combustion chamber therein should become choked because of lack of draft, the valve 2| Will automatically close and the oil or coal in the furnace cannot be ignited. Thus backfires and explosions are eliminated.

I claim:

The combination with the combustion chamber of a furnace and means for supplying fuel thereto, of an ignition tool for said furnace comprising a relatively long ignition pipe having its open forward end adapted to be inserted into the furnace chamber; an air valve mounted upon said ignition pipe at the rear end thereof and comprising a valve body for closing the rear end'of the ignition pipe, a valve chamber upon said valve body in communication with said ignition pipe, a gravity check valve in said valve body and a perforated dust cap enclosing said check valve body, a pair of spark plugs mounted in said ignition pipe, a gas supply pipe extending into said ignition pipe and terminating therein adjacent the said spark plugs, a gas control valve in said gas supply pipes and means operable upon the manipulation of said gas control valve for opening and closing an electric circuit to the said spark plugs.

IVER G. CARLSEN. 

